- Customers tend to spend money.
I think you can safely avoid "tend" on the TOEFL speaking section because this verb implies character judgment and is usually negative:
- He tends to drink too much.
- She tends to gossip.
Please use English well!
The global average TOEFL speaking score is 19. The Japan average score is 15. For our students who take 4+ months of classes, the average top TOEFL speaking score is 23. Why? Because they don't use templates! If you have a clear voice and practice regularly, you should get 23 consistently too.